The isolation of biological materials such as nucleic acids or proteins from complex biological mixtures such as clinical samples, e.g., whole blood, is of considerable significance especially for diagnostic purposes.
Numerous different methods have been developed in the art, e.g., denaturing, precipitating and removing undesired components in a sample with subsequent precipitation and isolation of the analyte in question (for example alcohol-based precipitation of nucleic acids).
Another approach is the binding of the biological material to be isolated to a solid support material which may be provided, e.g., in the form of chromatographic columns.
For diagnostic purposes, and especially for the automated isolation of biological materials subject to subsequent medium- or high-throughput analysis, binding particles are often used.
It is known in the art that during the isolation process often impurities are bound to the respective solid support and thus become co-isolated, and such impurities may interfere with downstream analysis of the biological material in question.
The prior art has attempted to deal with the above-mentioned circumstance by applying various measures.
For instance, the QIAprep® Miniprep Handbook (2nd Edition, December 2006) discloses a process in which the solid support is washed with chaotropic salts and ethanol, and CN101665785A discloses a solid support wash buffer containing Triton X-100. These approaches exhibit various drawbacks.